This invention relates to a technology that makes a production plan of products on the basis of demand forecast and required amounts from a sales side.
To improve profit in the manufacturing industry that gains a profit by manufacturing and selling products, it is necessary to promote the sale of the products and at the same time, to reduce the production cost. The key factor that determines the sales promotion and the reduction of the production cost is agility to demand fluctuation so as to flexibly cope with the demand fluctuation. The agility to the demand fluctuation can be achieved by shortening a planning cycle of the production plan and improving its accuracy.
Generally when a production plan is made, the production side calculates a producible number of products on the basis of the production request number from the sales side. MRP (Material Requirement Planning) is known as one of the calculation methods for calculating the producible number. According to this MRP, the name of the product to be produced ad the production request number of the product are inputted and a link processing for linking the product with parts necessary for producing the product is executed on the basis of a parts list to check producibility. When the parts are short, the production side requests the parts maker to advance the delivery term or to increase the number of ordered parts to satisfy the production requirement.
An example of the production planning system that employs MRP is described in JP-A-2000-79542. The production planning system of JP-A-2000-79542 includes a system for managing the demand of products and a system for managing the production of the product. The system for managing the demand of the product sends the production request number based on the demand of the product to the system for managing the production of the product and the latter executes MRP on the basis of the maximum acquirable number of parts at the present moment. When the parts are found short as a result of MRP, the system for managing the production of the product calculates a producible number of products on the basis of priority of products that is determined in advance and sends the calculation result to the system for managing the demand of the product. The system for managing the demand of the product decides the production execution number on the basis of the difference between the production request number and the producible number and manages the production of the product.
The MRP calculation process in JP-A-2000-79542 described above calculates the producible number by reverse-MRP on the basis of the priority of products set in advance under the condition that short inventory is not permitted when the short inventory occurs with respect to the production request number. The production planning system according to the prior art positions the request from the sales side and the forecast demand as only one solution and makes the production plan even though some of the production request from the sales side cannot be satisfied. Nonetheless, there occurs often the case where the request number can be satisfied if the plan is retarded by one day though the production cannot be made as required on the present day. The prior art technology cannot carry out the production of the production request number in such a case, too, because the request from the sales side and the forecast demand are the only solution, and the loss of sales opportunities occurs eventually.
When the inventory exceeding the production request number exists on the production side, the production side must conduct sales promotion activities to create the demand, to sell the product and to reduce the inventory.
The important aspect for promoting the sale and reducing the cost is the reduction of the loss of sales opportunities and inventory reduction beside the agility to demand fluctuations described above. To reduce the loss of the sales opportunities, it is necessary to correctly calculate the number of sets that can be practically produced on the production side in response to the production request number from the sales side and to reply the calculation result. The sales opportunities may be lost unless the production sides can instantaneously reply the correct producible number on the production side. Though the instantaneous calculation of the of the correct producible number of sets of products is thus very important, it has been difficult to correctly calculate the producible number in response to the production request when the number of kinds of products to be produced is great, the number of parts constituting the products is as large as several hundreds and moreover, the number of common parts among the products is great. In addition, no means has been available that increases and decreases the production number inclusive of products other than the requested product and correctly calculates the producible number of the product.
From the aspect of the increasing and decreasing the inventory, it is important for the production side to always grasp the surplus production capability for each product. For, it is possible to employ the market strategy such that the production side produces on its own judgment the producible product with the parts inventory and asks the sales side to sell the product to create the demand without always producing the product on the basis of the production request number from the sales side and the demand forecast.